Microsoft.Windows.Controls.Ribbon.RibbonTextBox.HookCommand C# (CSharp) Method

        private void HookCommand(ICommand command)
        {
            _canExecuteChangedHandler = new EventHandler(OnCanExecuteChanged);
            command.CanExecuteChanged += _canExecuteChangedHandler;
            UpdateCanExecute();
        }

        private static void OnCommandChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            RibbonTextBox textBox    = (RibbonTextBox)d;
            ICommand      oldCommand = (ICommand)e.OldValue;
            ICommand      newCommand = (ICommand)e.NewValue;

            if (oldCommand != null)
            {
                textBox.UnhookCommand(oldCommand);
            }
            if (newCommand != null)
            {
                textBox.HookCommand(newCommand);
            }

            RibbonHelper.OnCommandChanged(d, e);
        }